Pressure inducer



Jan. 12, 1965 H. c. EDWARDS 3,165,257

PRESSURE INDUCER Filed Oct. 5, 1962 2 Sheezi--Sheekl l i- Z Z Z172 SQCOCQCS INVENTOR. Howard C. Edwards Arron/VFY Jan. 12, 1965 H. c. EDWARDS PRESSURE INDUCER 2 Sheets-Sheet 2 Filed Oct. 3, 1962 INVENTOR.

s .m y d Em am, dg uy w HO@ FIG ATTORNEY United States Patent 3,165,257 PRESSURE ENDUCER Howard C. Edwards, 2443 Whipple Road NW.,

d Canton, Ghia Filed Get. 3, 1962, Ser. No. 228,194 4 Claims. (Cl. 230-127) The present invention relates to the art of inducing high pressure pneumatically and has particular reference to pressure blowers of the type suitable for materials handling.

In such systems, it has been found expedient toexpose the pressure blower to atmospheric' pressurewithin an enclosure and in certain instances to exhaust induced pressure within the enclosure; for in this manner, internal building construction heat is retained. yMaterials handling may be effected to transport flexible ribbon-like materials, granular and comminuted substances, dust particles, abrasive grains, cuttings from sheet-like materials 'by'creating from five Vto ten pounds pressure in the pneumatic tubes. This is accomplished by lintroducing the materials-handling high pressure blower and draft inducerl into a conduit between point of loading of conduit and unloading or exhaust. A typical example of the utility of "this system may be apparent from reference to the storing and transport of granulated insulating cork, where4 the invention is employed in lieu of a mechanical conveyor adapted to transfer granulated cork from hopper 011V unloading dock into a high material storage room.I Other v uses include installing the high pressure units in storage rooms to maintain same under constant negative pressure; lin this way exhausting dust-'ladenl air from storage rooms followingpassing same through a water spray scrubber, the motor, fans and bearings of the blower yunit being free of` and unaffected by dust, abrasive or other corrosive materials-handled. This invention is closely related to Patent 2,722,372, Draft Control Apparatus, issued November,` 1, 1955, on

an application filed April 2, 1952. In that invention, a draft control apparatus was defined in' which-wellY known fan means for artificially inducing draft was applied to the venturi-cone, fiue insert there patented. In thetpresent' instance, invention resides in the artificial draft inducerl per se,wherein means are provided'ifor creatinghigh pressure through low'output, the artificial draft inducing: meansbeing adapted to draft inducer flue assembly of size andvtype, due to the exaggeratedthrust transferredI v(if) to the motor bearings and moving parts. overcomes these problems. n

' With these and other objectives in view, the invention resides in the combination shown in the drawings wherein: FIG. l is a side elevational view of the invention, applied to a section of materials conveying conduit;

l FIG. 2 is a sectional View of the tubular exhaust of invention taken along lines 2 2 of FIG. l;

FIG. 43 is a view in vertical section of a fragment of the blower assembly taken along lines V3 3 of FIG; 1j FIG. 4 depicts the turbo blower wheel in perspective; FIG. 5 shows the blower wheel in topplan;

This invention FIG. 6 is a View in perspective of a blade of' the type employed in the FIG. 4blower wheel;

FIG. 7 is a Vvertical sectional View along lines 7-7 of FIG. 6.

Referring now to FIG. 1, the high pressure assembly 100 is shown to include draft control flue, insert 110, this being a section of tubular conveyor conduit, said draftrcontrol insert including plenum chamber 112, the walls of which diverge in a dihedral from the circumference of the conduit and are connected at their opposite end to pressurized air expansion conduit 114, said expansion conduit being connected as at 116 to the artificial air blower '100. The plenum Vchamber 112 has been expanded in volumetric area over that shown in Patent 2,722,372 above recited. In practice on a hig'npressure blower of 43l diameter I intend to create 6-7#,pressure l in the system by turning the blower wheel at 3600 r.p.m.

A typical pilot installation has included a stainless steel materials handling tube 77 long, 60 H.P., 3,450 rpm. motor journalled to aV high pressure blower of the type shown herein, exhausting into a 13' xk l5 x 15 I storage room, pulling through 400 ft. of open 8" pipe.

Negative static pressure readings taken 7 diameters. back of the compression and expansion chamber were 17.6 W.G., velocity 11,676 fpm. pulling ft.; 18.6 W.G., velocity 9,306 f.p.m. pulling 270 ft.; 19.3 W.G., velocity 6074 fpm. pulling 400 ft.

cover 122 having a central air inlet aperture 124, boundedy on its exterior by a plurality of reinforcing span trusses 126. This removable cover 122, which may be dened as a first radial wall, together withA second radial wall 130 and a por-tion of annular wall 134 define the pressure chamberor pumping chamber 128, best shown in FIG.y

3l `A thirdradial wall 136 land axial wall 137 cooperate with the remaining portion of peripheral wall 134, and with bafiie extension 132 of wall 130 to`forrn collecting chamber 129. The outward edge of baflie132 and opposite peripheral wall 134A define a restricted annular open-I ing between pumping chamber 128 and collecting chamberv Referring now to the pressure chamber 128,` it will be noted that it is circular in configuration, having its annular wall 134 spacing the cover 122 from rear vwall 130. Centrally of the depression formed by the rear wall of the chamber 128 is a suitable aperture for the shaft 180, said shaft connecting the'motor to the fan of FIGS.A 4 and 5.

The fan 151i shown in FIGS. 3, 4 and 5 includes two basic discs rigidly held in spaced relation by a plurality of radially extending blades 160. More specifically, fan comprises discs 152 and 156 respectively, the outer disc 152 being of frusto-conical design and having an y aperture 154 centrally thereof to receive pressure at zero atmospheres. It will be noted that the sloping design of the disc 152 from center outwardly, is such as to conform to the related configuration of the blades 160, one of which is shown in FIGS. 6 and 7. Adjacent aperture 154 the conical disc is curvilinear in cross-section. See FIG. 4 in this connection.

The inner counterpart of disc 150, namely blade supporting member 155 comprises a plurality of superposedflat plates, each of decreasing diameter with respect to the other. Three such discs are shown in FIG. 3. Each of the respective plates comprising disc 156 is held contiguous to its smaller counterpart, lendingkto the aluminum load bearing disc l156 a reinforced axle-engaging center kcom- Patentecl Jan. 12, 1965 plemental to hub 170 which is leyed to the shaft 130 as shown in FIG. 3. The largest of plates 156, engaging the jblades, is pressure relief apertured kat 158 in a concentric ring of apertures, 29% along a radian-from the peripheryy of the disc. In a 43 diameter wheel, for example, the apertures are twelve in number and placed v at 12% from the center outward, the apertures being 7/s to 11/s" in diameter. The ratio of a 43 diameter wheel area to aperture area is 1452 sq. in. to .6013 sq. in. for a '/s aperture or .9 940 sq. in. for a 1% aperture.

The smallestA circular plate 174 is made of steel 'as isthev end hub 178. The effect of these elements is to bind the aluminum blower wheel to the shaftduring high pressure operation as will be apparent. t

vAs indicated, the blower'wheel apertures 158 control end thrust pressure on the motor, bearings, reducing it toV zero, ideally. For smaller diameter flowl systems 260 using the lsame blower wheel the apertures )vill be increased in diameter to compensate for the increased pressure.' If one were to increase the sizeof the relief apertures more than necessary to accommodatefor the pressure on the thrust bearings, a reverse action wouldtake place and the thrust by centripetal action would drive into the. motor on the drive shaft. kThis is due to the factthat the relief apertures lrelease the pressure normallyy but, if increased too great, the pressure would shift to the forward face of the blower wheel forcing it inwardly` and causing excess thrustfon the bearings.

It will be appreciated from'FlGS. 5 and 6 thatV the blades 160 each comprise a unitary shaped element, havingiiat base 162, said base` being adapted to rest contiguous the disc-156 and secured thereto by bolting, riveting or other suitable means. An upright wall 164iseparating the respective portions 152 and 166 is provided;

normal to the respective 162 andl' surfaces. Howeyer,

at its innermost extremity, considering the overall fan construction of FIGS. 4 andV 5, wall 164 of the blade is of increased area when compared to its outermost extremity`168, Declination angle of the topsurfaceluti is preferablyat two (2) degrees.

The intake nozzle124 which is best shown at FIG. 1

, is secured to the outwardly extending curvilinear aperture formed by the housing 120. The design of this member is such as to insure maximum atmosphere input-tol, the device, commensurate with its outputcapacity. ,Hera

the inner` extensionof the respective blades 1,60 is such ofthe blades of the fan as sloping at the input Aend and cut away at 168, the upper portion adjacent the outwardly extending aperture of the upper disc. By design, Vthe respective blades are given rigidity through corrugation as well as fixed attachment, exteriorly and interiorlv between the respective outer compression and inner support disc 150 and 156 respectively. The design ,of discs, apertures thereof and blades is to insure maximum con active results `in directing and compressing the intakey and output.

In operation, the tlow of air issuch thatrupon exhaust of the highly compressed air from the peripheral'aperture provided between Vthe respective `compression and base Y, as to also Prmit 'maximum input commensurate with output capacity, reference being made to the configurationr 212 and 214 of asbestos or glasswool. FIGURE 2. The angle of inclination of the walls from front to rear is at 2. The interior tubular portion 220 is likewise apertured at 218, the apertures being alternately misaligned,

' to give noise access to the laminates 212 and 214. The

inner laminate 214 is highly.v compressedwith respect to the outer 212. In practice, a satisfactory muiiier is being made without exterior aperture 210. In this-muffler,

the design being divergent, the apex ofthe induced draft shall occur in the vicinity ofy but just short the point of maximum inner circumference, `thereby creating an ever` more etfective'system ofcnoise control.

Whereas the invention has -been defined with specific reference to materials handling kthrough pneumatic induction,-i t will be obvious to thoseskilled in the art that it may likewisev be adapted to otherv systems of pressure control such yas heating and cooling without departingk from the spirit of the invention as 4set forth Vin the vappendedfclaims.

Whatis claimed is: Y 1. In a pneumaticv pressure inducer havinga driving means provided with a forwardly extending driving shaft,

the improvement comprising: a sheet metahrotor mountedfon the forward end of .said shaft; saidrrotor having a central hubrkeyed torsaid shaft,`an,end plate secured to said hub andlto said shaft for limiting Laxial displacement of said rotor relative to the shaft, an annular blade supporting memberV secured tothe vopposite yend of said hub from said end plate andextending radially from said hub in a plane normal to the axis of the shaft, said` iiat walls vand a peripheralrannular wall'securedtto thel first.A and third Walls;l saidrrst and second wallsand a portion: of said peripheral `wall defining al pumping chamberfor the rotor; said `second and third walls and ha remaining portion of said peripheral wall defining a collecting'chamber; `said ,second Wall and `said peripheralwall defining therebetween a restricted annular opening for communication betweenrthe pumping ychamber andthe `collecting chambergsaid housing having a tangential, out-l wardly converging Ydischargeoutlet communicating with'y said collecting chamber; said rotor'having ay plurality ofV holes in the vdisc Vhavingthe largest` diameter, equally discs 152Y and 156, the air passes into'expansion chamber 128 whereby it is permitted to expand and maintain cool-v ness, -While rotating counterclockwise inthe direction of tangential outlet-1%, provided at the ybottom ofthe fan housing. The` outlet channel 116 for the highly compressed air is set conventionally substantially tangential to the circular exterior of the housing. This principle is well recognized in draft inducing fan manufacture and is'shown in Patent 2,722,372` Y With regard to the draft inducing ,pipe assembly, a design comparable tothatof Patent 2,722,372 While employed herein, includes the sound muling attachment 2MB. This comprises a tubular extension of Miles steel in which concentric and foraminous tubes121tl contain laminates spaced radially from the axis of the rotor, whereby axial thrustsV on the supporting discY and on'. the conical disc are .equalized;, yand means in said first wall providing communication with theintake of the rotor.

2. The improvement of claim v1 wherein said end plate and the disc having the smallest diameter .aretcons'tructed of steel, and the remainder of said of aluminum. Y,

3..,"1`he improvement of claim 1'y furth r comprising a bolt received in a central aperture of said end plate and threadably Vreceived in said shaft, thereby locking `said rotor; against axial movement on said shaft.

4,.'l`heimprovement of claim 1 wherein, each of said blades comprises a central face defining first and second longitudinallyV orientedy converging edges and flanges integrally formed at said longitudinal edges, said flanges being turned yaway Vfrom each other normallyto vsaid facefand a divergent-end:` of one of said anges being cut away, thereby-partially defining an intake. i

(References on followingipage) rotor is constructed 5 6 References Cited by the Examiner 2,641,191 6/53 Buch 230--134 UNIT D STATES PATENTS 2,899,129 8/ 59 Schwaiger 230-134 E 2,991,844 7/61 Nomar 230-134 Re. McCracken 2 Heinicke 1,330,547 2/20 Mehlhof 230-127 5 (2) gleents References Cited bythe Applicant en ey 1,676,946 7/28 Fechheimer 23o-134 UNITED STATES PATENTS 1,754,724 4/30 Mead 230-133 3,010,697 11/61 Lazo. 1,862,523 6/ 32 Anderson 23o-133 10 3,044,683 7/62 Woollenweber. 2,069,640 2/ 37 Beardsley 230-127 3,077,297 2/ 63 Clarke. 2,285,338 6/42 Kidney 230-133 2,537,084 1/51 Pfarre,- 103 .114 JOSEPH H. BRANSON, JR., Przmary Examzner. 

1. IN A PNEUMATIC PRESSURE INDUCER HAVING A DRIVING MEANS PROVIDED WITH A FORWARDLY EXTENDING DRIVING SHAFT, THE IMPROVEMENT COMPRISING: A SHEET - METAL ROTOR MOUNTED ON THE FORWARD END OF SAID SHAFT; SAID ROTOR HAVING A CENTRAL HUB KEYED TO SAID SHAFT, AN END PLATE SECURED TO SAID HUB AND TO SAID SHAFT FOR LIMITING AXIAL DISPLACEMENT OF SAID ROTOR RELATIVE TO THE SHAFT, AN ANNULAR BLADE SUPPORTING MEMBER SECURED TO THE OPPOSITE END OF SAID HUB FROM SAID END PLATE AND EXTENDING RADIALLY FROM SAID HUB IN A PLANE NORMAL TO THE AXIS OF THE SHAFT, SAID SUPPORTING MEMBER COMPRISING A STACK OF ANNULAR SHEET METAL DISCS OF DECREASING RADIAL DIAMETER, A PLURALITY OF BLADES FIXED RADIALLY ABOUT AN AXIS OF THE DISC HAVING THE LARGEST DIAMETER AND CONCENTRICALLY SPACED ABOUT THE AXIS, EACH BLADE HAVING A GENERALLY TRIANGULAR SHAPE COVERGING A RADIALLY OUTWARD DIRECTION, AND LYING IN A GENERALLY RADIAL PLANE, A CONICAL DISC SECURED TO CONVERGING SIDES OF THE BLADES AND DEFINING A CENTRAL INTAKE OPENING FOR THE ROTOR; A SHEET METAL HOUSING MOUNTED CONCENTRICALLY ABOUT SAID ROTOR AN ENCLOSING THE SAME, SAID HOUSING COMPRISING FIRST, SECOND AND THIRD AXIALLY SPACED, FLAT WALLS AND A PERIPHERAL ANNULR WALL SECURED TO THE FIRST AND THIRD WALLS; SAID FIRST AND SECOND WALLS AND A PORTION OF SAID PERIPHERAL WALL DEFINING A PUMPING CHAMBER FOR THE ROTOR; SAID SECOND AND THIRD WALLS AND A REMAINING PORTION OF SAID PERIPHERAL WALL DEFINING A COLLECTING CHAMBER; SAID SECOND WALL AND SAID PERIPHERAL WALL DEFINING THEREBETWEEN A RESTRICTED ANNULAR OPENING FOR COMMUNICATION BETWEEN THE PUMPING CHAMBER AND THE COLLECTING CHAMBER; SAID HOUSING HAVING A TANGENTIAL, OUTWARDLY CONVERGING DISCHARGE OUTLET COMMUNICATING WITH SAID COLLECTING CHAMBER; SAID ROTOR HAVING A PLURALITY OF HOLES IN THE DISC HAVING THE LARGEST DIAMETER, EQUALLY SPACED RADIALY FROM THE AXIS OF THE ROTOR, WHEREBY AXIAL THRUSTS ON THE SUPPORTING DISC AND ON THE CONICAL DISC ARE EQUALIZED; AND MEANS IN SAID FIRST WALL PROVIDING COMMUNICATION WITH THE INTAKE OF THE ROTOR. 